Chernobyl, 20 Years After the Disaster

A worker walks by the remains of the Chernobyl Nuclear Power Plant's reactor number four. In the seven months following the 1986 explosion, Soviet engineers hastily designed and built a massive concrete-and-steel sarcophagus to enclose the reactor building and its smoldering core. The shell, however, was only meant to last 20 to 30 years, and it has deteriorated badly.

Work is set to begin soon on a new stadium-size shelter that will confine the entire reactor building and the radioactive material within for at least a hundred years. The project is estimated to cost the equivalent of 950 million U.S. dollars and be completed by 2008.